Two key dimensions of the aging process are physical health and psychological well-being. Aging well in both dimensions has been linked with a host of factors such as control, social support and stressful life events. Using a longitudinal family design, the proposed research will focus on these major dimensions associated with optimal aging, assessing both the directionality of these relations and familial influence on individual differences in physical health and psychological well-being and their correlates. First, a longitudinal follow-up of participants in the Study of Optimal Aging will be done using a multidimensional battery of gerontologically relevant measures, and linear panel analysis will be used to assess relations between the variables over time. Second, the siblings and children of the sample will be assessed on a similar battery of measures. Correlational analyses will be used to assess familial influence on individual differences on the behavioral phenotypes associated with optimal outcomes. The design will also permit comparisons between parent-offspring and sibling resemblance which may suggest generational differences in family resemblance. Although family studies cannot disentangle genetic and environmental sources of familiar resemblance, they are valuable for several reasons. For example, family studies suggest upper-limit estimates of the influence of additive genetic effects (genetic influences that "breed true" among siblings) which can be no greater than twice the phenotypic sibling correlation. Family studies also provide important comparison data for the results of twin studies. Finally, family studies make it possible to study nonshared environments by identifying environmental factors that make siblings different from one another.